Variable thread-controlling mechanism for sewing-machines.



LONDERDONK. VARIABLE THREAD CONTROLLING MECHANISM FOR SEWING IIIIACHINES.

APPLICATION FILED MAY 24. I916.

Patented Aug. 27, 1918,

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APPLICATION FILED MAY 24, 1915.

Patented Aug. 27, 1918.

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APPLICATION FILED MAY 2.4. 1916.

Patented Aug. 27, 1918.

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I 'L. ONDERDONK VARIABLE THREAD CONTROL HHS MECHANISM FOR SEWING MACHINES.

APPLICAHON FILED MAY 24 l9l6.

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reference marked. thereon.

Lemme oivnnanourz, or new YORK, N. Y., Assmivca TO UNION SPECIAL MACHINE CGMPANY, OF CHICAGO, ILLINOIS, A COBPQRATIGN OF ILLINOIS.

vesmsts TnnEAn-co vraomme MECHANISM FOR snwmc-mncmuns.

Specification of Letters Patent.

Patented Aug. 27,1918.

Application filed May 24, 1916. 7 Serial No. 99,622.

Thread-Controlling Mechanisms for Sew .ing-lviachines, of which the following is a description, reference bemghad to the accompanying drawing andto the figures of The-invention relates to new and useful improvements in variable thread controlling mechanisms for sewing machines, and more particularly to a thread cont-rolling mecha nism for the looperthread in a'chain stitch sewing machine.

An object of the invention is to provide a thread controlling mechanism wherein two thread engaging devices may be given a differential movement relative to each other in certaintimed relation to the movement of the lcopers for giving up and taking up thread in addition to their bodily travel in the same direction to give up and take up thread.

A further object of theginvention is to 7 provide means whereby the differential I ,ee

movement of said thread engaging devices relative to each other may be varied.

These and other objects will in part be. obvious and willin part be hereinafter more fully described.

In the drawings, which show by way of illustration one embodiment of the invention:--

Figure 1 1s a View, -1n front elevation, showing a machine having my improved thread controlling mechanism applied thereerating lever, the operating rock shaft, and the means for actuating the same from said lever Fig. 6 is a detail, partly in side elevation and leaving the needle thread loop.

and partly in section, showing the bed plate, the rock shaft, and the devices for operating the looper support therefrom;

Fig. 7 is a detail showing the operating arm for actuating the looper' support inv plan; Fig. 8 isa view show1ng,-niore or less diagrammatically, the work. support, the looper and the needle, the looper'being at the rear end of its stroke in full lines and at the forwardend of its stroke in dotted lines;

F ig. 9 is a view showing, more or less diagrammatically, the position of the thread controlling elements when the looper is at the'i'ear end of its stroke;

"Fig. 10 is a similar View showing the thread engaging devices having finished their differential movement and moving bodily together, the looper at the point having ust well entered the needle thread loop;

Fig. 11 is a similar view with the looper at the forward end of its stroke and. the

thread controlling elements having completed their movement.

The improved thread controlling mechanism is especially adapted for a looper which moves back and forth in the general direction of the line of feed when enter i ng he thread supply is from a direction at right angles to the travel of the looper and as a consequence the first part of the forward movement of the looper gives slack to the thread very rapidly. It is essential, therefore, that the thread controlling mechanism should be so constructed as to take up thread during the first part of the forward move ment of the looper. After the looper point has.. entcred the needle thread loop then thread should be given to the looper to prevent the breaking of the looper thread during the last part of the forward movement ofthe looper. It is essential also, therefore,

that the thread controlling mechanism shopld be so constructed as. to give up thread at this time. On the first part of the backward movement of the looper, the-looper the loope -thread should therr bej'given to the loopenso that the stitches may be drhwn up and set without having the looper pull its thread against the needle. It is again essential that this thread controlling mechanism should maintain the thread substan tially taut as the looper starts back and then finally give up thread to the looper.

In order to accomplish this controlling of the thread, I have provided two thread engaging devices which are capable of moving bodily together for giving up and taking up thread and which are also capable of having a differential movement relative to each other for giving up and taking up thread.

Referring more in detail to the drawings, I have shown my improved thread controlling devices as applied to a sewing machine having a supporting bed 1 on which is mounted an overhanging arm 2. The needle bar 3 reciprocating in the outer end of the overhanging arm is provided with a plurality of needles 4. The needle bar is reciprocated by a needle lever 5 which is pivoted at 6 to the overhanging arm, and said needle is oscillated by an eccentric strap 7 cooperating with an eccentric on the main shaft 8. Said eccentric strap 7 is pivotally connected to a ball Stud 3 on the needle lever.

Cooperating with each needle beneath the work support is a looper 10. These loopers are mounted on a looper carrier 11 which,

in turn, is mounted on a looper support 12.

The looper support is in the form of a shaft and is mounted to oscillate and slide endwise in bearings 21 and 22. On the extreme inner end of the looper support 12 is a sleeve 23 carrying ahead 24 in which is slid-v ably mounted a pin 25 having a ball 26 on its outer end. This ball 26 is adapted to be connected to an arm 27 carried by a rock shaft 28. The rock shaft is mounted on a stud 29 clamped to the supporting bed 1.'

The rock shaft is also provided with anarm 30. This arm.is connected to a lever 31 by a link 32. The lever 31 is oscillated by an eccentric 33 which cooperates with an eccentric on the main shaft 8. This looper mechanism per 86 forms no part of the present invention, but is shown, described and claimed in my co-pending application, Serial No. 99620, filed of even date herewith.

The looper mechanism, however, has been described sufficiently in detail so that it will be underst-ood'that the loopers are moved back and forth in the general direction of the line of feed. The looper support is moved endwi-se as well as omillated, and the train of mechanism referred to above is so constructed as to move the looper in a foramt-a sufficiently and moved laterally to permit the needle to pass between the thread and the body of the looper. A

The looper threads are indicated at Z. There is a separate looper thread for each looper. My improved thread controlling mechanism for the looper threads operates in precisely the same way for each looper and for the sake of ,clearness will be de scribed as operating upon a single thread. The looper thread is led from the supplythrough a suitable tension T, and thence through a thread guide 35. After leaping the thread guide 35, the looper thread passes through a thread eye formed in an arm 37 fixed to a shaft 38 which is mounted to oscillate in a supporting bracket 39. This supporting bracket 39 is secured to the bed plate 1 by screws 40 which pass through elongated slots in thebracket, thus permitting the bracket to be adjusted in the direction of its length or toward and fronrthe looper. The looper thread passes through the guiding eye 36, thence around a pin 41 mounted on an arm 42 which is adjustably attached to the needlelever extension The shank of the arm '42 is slotted at 44, and a screw 45 passing through said slot and into said. lever extension holds the arm in an adjusted position. This permits this arm to be adjusted toward and from the looper. The thread Z after passing around shaft 38 is oscillated by a link 52 which is pivoted at 53 to the needlelever extension 43. Said link 52 is pivoted at 54 to an arm 55 fixed to the shaft 38.

From the above, it will be apparent that, when the. needle lever extension 43 is escillated, both the arm 37 and the arm 42, that is, the thread engaging devices, will move bodily toward and from the looper, giving up andtaking up thread. It will also be apparent that, when the arm 37 is moved to its extreme right hand position, as shown in Fig. 9, the link 52 and the needle lever extension 43 are substantially in alinement. This results in the following action upon the thread engaging devices: When the parts are first moving from the position shown in Fig. 9, the thread arm 42 moves forward with the needle lever extenslon, while there is very little or no movementgiven. to the-arm 37 owing to the fact that the link 52 is substantially in alinement with the needle lever extension 43. This results.

- I have shown the looper at the rear en .of

.the link 52 reaches a position so as to osc1lits stroke, and as it moves forward, the forward movement of the pin 41 relative to the arm 37 takes up the slack given up by the looper. This prevents the forming of slack thread in front of the eye of the looper which might cause the kinking of the thread or the wiping of the looper thread around the looper or a shoving of the needle thread loop to one sideand preventing the looper from entering the needle loop. As soon as the looper point is well into the needle loop,

late the arm in substantially the same timing as the movement of the arm 42. This position of'the parts is shown in Fig. 10. From this time on or until the looper reaches the forward end of its stroke, the arm 36 and the arm 42 .are. moving toward the looper bodily together'and giving up enough thread which permits the looper thread to be free from tension when the stitch is set,

thereby causing the looper thread loop in the stitch tobe relatively long and lie flat against the under surface of the fabric. When the looper begins its backward movement, both the arm 42 and the arm 37.move' rearwardly together, taking up the slack in the looper thread caused by the backward movement of the looper, and thisholds the looper thread taut sothat the needle will with certainty pass between the looper thread and the body of the looper. After the needle has gotten well down past the looper thread, the arm 37 has reached the rear end of its stroke and the arm 42 moving toward the arm 37 gives up thread to thelooper, permitting it to move freely back to the rear end of its stroke.

From the above description, it will be apparent that I have provided a thread controlling mechanism for the looper thread wherein the thread engaging elements move. bodily back and forth to take up and give up looper thread, and wherein'one of the elements moves relative to the other to give up and take up thread. By adjusting the position of the bracket 39, the amount of dwell given to the thread arm 3'i'.may be ,varied. Thus the amount of thread pulled up by the difi'erential movement between the two arms 42 and37 vary.

The arm 42 may of the bracket 39 and so as to properly position the arm 42 relative to the arm 37.

Having thus describedthe invention, what is claimed'as new is 1. The combination with a looper moving in the general direction of the line of feed, of a thread controlling mechanism therefor, including two thread engaging elements and devices for moving said elements bodily. in the same direction for taking up looper thread and in the opposite direction for giv ing up looper thread, said devices having means'for moving one of said elements rela* tive to the other during said taking up action for giving up thread, and during said giving up action for taking up thread.

2. A looper thread controlling mechanism including in combination two movable thread arms, and devices for moving said thread arms to give up thread to the looper on its forward stroke, said devices including means for moving one thread arm relative to the other to take up looper thread on the first part of said forward stroke.

3. A looper thread controlling mechathreacl arms, and devices for moving said thread arms in the same direction for taking up looper thread on the backward movement of the looper, and said devices including means formoving oneof said arms relative to the other to give up thread during the backward movement of the looper.

4. A looper thread controlling mechanism for sewing machines including in combination, two thread arms, and means for moving one thread arm' relative to the other for taking upthread onthe first part of the forward movement of the looper for substantially moving said arms together to give up thread to the looper as it completes its for ward movement.

5. v A looper thread controlling mechanism for sewing machines including in combination, twothread arms, and means for moving one thread arm relative tothe other for taking up thread on the first part of the forward movement of the looper for substantially moving said arms together to give up thread to the looper as it' completes its forbe adjusted so as to permit the adjustment:

nism for sewing machines including two ward movement, and for-moving said thread v arms for taking up thread on the first part of the backward movement of the loopers and for subsequently moving said arms-relative to each other for giving up looper thread as the looper moves to the rear end of its stroke.

6. A looper thread controlling mechanlsm for sewing machines including in com bination, a thread arm, a shaft supporting said arm, an oscillating lever, a thread arm carried thereby, -a-'link connecting said lever to said shaft whereby thefishaft.

is oscillated by said lever, said f link and lever being so constructed and ar-' ranged as to move into alinement to give a dwell to the shaft, whereby said thread arms may have a relative movement and a bodily movement together as the lever moves in either direction.

7. A looper thread controlling mechanism for sewing machines including in combination, a thread arm, a shaft supporting said arm, an oscillating lever, a thread arm carried thereby, a link connecting said lever to said shaft whereby the shaft is 0scillated by said lever, said link and lever being so constructed and arranged as to move into alinement to give a dwell to the shaft, whereby said thread arms may have a relative movement and a bodily move ment together as the lever moves in either direction, a bracket for supporting said shaft, and means for adjusting the position of the bracket in the plane of oscillation of the lever whereby the differential movement imparted to the thread arms maybe varied.

In testimony whereof, I affix my signature, in the presence of two witnesses. LANSING ONDERDONK. lVitnesses:

JOHN H. HOWELL A. J. VVAREING. 

